Jennings I, Kitchen S, Woods T A, Preston F E, Greaves M
UK NEQAS for Blood Coagulation and Coagulation Laboratory, Royal Hallamshire Hospital, Sheffield.
Thromb Haemost. 1997 May;77(5):934-7.
The identification of the presence of antiphospholipid in plasma is recognised to be of diagnostic and prognostic importance in subjects with thrombotic disease, recurrent miscarriage or collagen vascular disorders. A number of coagulation assays are currently employed for the detection of lupus anticoagulant (LA), many of which are influenced by reagent dependent and methodological variables. In the present study lyophilised plasma samples from three subjects with "strong", "weak" and "absent" LA were tested in 220 centres. The most commonly used tests for LA were Activated Partial Thromboplastin Time (APTT), Dilute Russell Viper Venom Time (DRVVT) and Kaolin CLotting Time (KCT). Median DRVVT ratios were 1.75, 1.17 and 1.10 for the three samples. The presence of a strong LA was not detected by 4% of laboratories. The correct diagnosis was made by 94% of users of DRVVT and 85% of users of KCT. A weak LA was not detected by over half of centres. Correction was observed on addition of plasma and also in platelet neutralisation. The correct diagnosis was made by 37% of users of DRVVT and 27% of users of KCT. Lupus Anticoagulant was falsely considered to be present in a Factor IX deficient plasma by approximately one quarter of laboratories. Amongst users of DRVVT and KCT absence of LA in this sample was correctly reported by 73% and 69% of centres respectively. The accuracy of testing for LA in the present study is suboptimal and this is likely to have important clinical consequences. There is clearly a need for greater conformity in the selection and performance of LA tests to facilitate accurate diagnosis of this important group of disorders.
血浆中抗磷脂的检测对于患有血栓性疾病、复发性流产或胶原血管疾病的患者具有诊断和预后的重要意义。目前有多种凝血试验用于检测狼疮抗凝物（LA），其中许多试验受到试剂依赖性和方法学变量的影响。在本研究中，来自三名LA“强”、“弱”和“无”的受试者的冻干血浆样本在220个中心进行了检测。最常用于检测LA的试验是活化部分凝血活酶时间（APTT）、稀释蝰蛇毒时间（DRVVT）和高岭土凝血时间（KCT）。三个样本的DRVVT比值中位数分别为1.75、1.17和1.10。4%的实验室未检测到强LA的存在。DRVVT使用者中有94%、KCT使用者中有85%做出了正确诊断。超过一半的中心未检测到弱LA。在加入血浆以及血小板中和时观察到了纠正现象。DRVVT使用者中有37%、KCT使用者中有27%做出了正确诊断。约四分之一的实验室错误地认为IX因子缺乏血浆中存在狼疮抗凝物。在DRVVT和KCT使用者中，分别有73%和69%的中心正确报告了该样本中LA的缺失。本研究中LA检测的准确性欠佳，这可能会产生重要的临床后果。显然，在LA检测的选择和操作方面需要更大程度的一致性，以促进对这一重要疾病组的准确诊断。
